Tip 13: Long hours of work are making more American marriages stressed and frustrated: statistics show that 13 percent of couples have sex only a few times a year and 45 percent have sex just a few times a month. If it?s time to address sexual issues in your marriage or relationship, make an appointment with a urologist for both people in the couple.

Married heterosexual couples enjoy better health than same-sex couples who live together, according to a study funded by Rice University.

Same-sex couples who live together have about the same level of health as opposite-sex couples who live together. The research may point to the advantages of marriage regardless of whether it is a same-sex couple or not, according to the authors of the study.

"Previous studies have indicated there are health disadvantages to living together versus being married, but almost no previous research has focused on same-sex couples," Justin Denney, assistant professor of sociology, associate director of the Kinder Institute Urban Health Program at Rice and the study's lead author said in a press release. "This study is one of the first to show that the mental and physical health disadvantages of unmarried couples living together may extend to same-sex couples."

According to researchers, the results are surprising because previous research shows a strong correlation between higher socio-economic status and health.

Cohabitating same-sex couples have average household incomes of $10,000 more per year than married couples and about $18,000 more per year than cohabiting opposite-sex couples.

The study, published in the Journal of Health and Social Behavior, is based on surveys of self-rated health conducted between 1997 and 2008 as part of the National Health Interview Survey. About 3,200 unmarried people in cohabiting same-sex relationships, 20,000 unmarried people in cohabiting heterosexual relationships and 400,000 people in married opposite-sex relationships were interviewed.